Do Ewido and KAV share the same sig database?

Today's Ewido update reported an FP on the same file as KAV (with extended databases). No other AT or AV that I scanned this file with alerted. Since this is a recent FP for both Ewido and KAV, I was wondering whether they share signatures and both have basically the same database? Anyone know?

It was a Viewer associated with Shareaza. None of the other AVs or ATs alerted other than Ewido and KAV and both have responded that it is an FP. Interestingly, they both gave the FP during the same update cycle. That is why I was wondering.